Which water heating method provides hot water instantly?

The method of heating water that provides hot water instantly is the combi boiler. A combi boiler, or combination boiler, heats water directly from the mains supply as you use it, which means there is no need for a hot water storage tank. This on-demand heating allows users to access hot water almost immediately when they turn on the tap, making it ideal for locations where space is limited or where quick access to hot water is a priority.

In contrast, a conventional boiler heats water in advance and stores it until needed, which can result in waiting for the water to heat or run out during use. Similarly, a gravity-fed system relies on a cold water tank and a hot water cylinder, leading to delays in hot water availability. A storage tank system also pre-heats water and stores it, which does not offer the same instant access as a combi boiler does. Thus, the unique feature of the combi boiler providing hot water instantly makes it the correct choice.